The invention relates to a briefcase, more particularly to a briefcase which has elastic properties and tensile strength.
Referring to FIGS. 1 and 2, a conventional briefcase is shown to comprise a pair of casing halves A and a first and a second briefcase frame B, C. The casing halves A are usually made of Acrylonitrile-butadiene-styrene (A.B.S.) and are shaped as shallow rectangular pans with a protruding looped lip Al formed on a peripheral edge. Each of the first and second briefcase frames B, C has an engaging groove for press-fitting with the looped lip A1 of one of the casing halves A. A pair of sheet members are attached to the rear ends of the first and second briefcase frames B, C to hinge the two briefcase frames B, C together. The briefcase further includes a handle piece B2 and locking means B3, B4 for holding the casing halves A in a closed position.
When manufacturing the conventional briefcase in FIGS. 1 and 2, an A.B.S. plate is first cut to the desired dimensions and then undergoes a thermal forming process to shape the casing halves A and the protruding lips A1. The first and second briefcase frames, B and C, are then press-fitted against the casing halves A and a pair of sheet members are attached to the rear of the briefcase frames B and C to hinge the briefcase frames B and C together.
The disadvantages of using an A.B.S. briefcase are as follows:
(a) The A.B.S. briefcase is easily deformed and suffers from scratches, cracks and dents when accidentally bumped into another object.
(b) The A.B.S. briefcase is easily affected by temperature conditions. Extremely high or low temperatures change the characteristics of the briefcase and cause the same to become brittle.
(c) Because of the rigid characteristics of the A.B.S. briefcase, the manufacturing process is too noisy.
Conventional briefcases may also be made of flexible plastic materials, such as synthetic leather, to overcome most of the above mentioned disadvantages. However, production cost of these briefcases is higher and at the same time, production time is longer because sewing machines are used to assemble the briefcases.